Hydrocarbon conversion



A. H. SCHUTTE 2,789,084

HYDROCARBON CONVERSION Filed June so, 1954 April 16,1957

I/e/az Y INVENTOR gORNEY eration, each under the most favorableconditions. 7 possible to conduct operations according to my new pro-United States Patent F HYDROCARBON CONVERSION August H. Schutte,Hastings on Hudson, N. Y., assignor to The Lummus Company, New York, N.Y., a corporation of Delaware Application June 30, 1954, Serial No.440,321

13 Claims. (Cl. 196-55) This invention relates to the conversion ofhydrocarbons in a freely-flowing, gravity-packed bed of granularmaterials to simultaneously produce high yields of coke and gaseousunsaturated lower hydrocarbons.

This application is a continuation-in-part of the invention disclosed inmy co-pending application, Serial No. 191,543, filed October 23, 1950,now abandoned, and entitled, Hydrocarbon Conversion, which is acontinuationin-part of copending application Serial Number 651,598,filed March 2, 1946, now Patent No. 2,526,696 and entitled Process forthe Simultaneous Production of Coke and Gaseous Unsaturated Hydrocarbonsand Apparatus Therefor. In this earlier case, reference has been made tothe cracking of various heavy hydrocarbons by the introduction of thehydrocarbon charge to a point below the surface of a preheatedcontinuously-moving bed of porous solids which passes through a confinedreaction and regeneration zone solely by gravity. It has been pointedout that the contact material may be inactive or inert, serving only asa heat carrying material and as a coke repository. Proper control of theratio of charge to contact material prevents gumming, sticking, orcementing of the particles in the bed.

It has also been pointed out that the temperature limits possible insuch an operation are dependent only on the character and properties ofthe contact material and that the normal temperature limitation ofcracking in a tubular heater is avoided. It is Well known, of course,that except for relatively light stocks, temperatures in a tubularheater cannot be excessive because of the undesirable coke depositionformed on the tubes under these conditions. It is for this reason thatcharge stocks boiling above 800 F. to 900 F. (at atmospheric pressure),as well as most residual stocks, have usually been sold as residual fueloil.

In accordance withthe present invention, it is found desirable toindependently control two portionsof the same heated stream of granularmaterials and to thus operate a liquid phase operation and a vapor phaseop- It is cess at temperatures substantially higher than has heretoforebeen the case, as for example, in the so-called thermal cracking asconducted in tubular heaters.

With the substantially higher temperatures at which both the liquid andvapor cracking are accomplished (especially the latter), only a veryshort time is required for completion of the reaction. Furthermore it ispossible to obtain a precise control of the various reactions byindependently maintaining the separate zones in such a manner that boththe liquid-coking reaction and the vaporcracking reaction are conductedat maximum efiiciency, each at the desirable temperature.

According to my present invention I feed a heavy residual charge stockto an upper part of a liquid-cracking zone and permit a portion of theliquid to crack and distill ofi, the residue being eventually convertedto coke.

Patented Apr. 16, 1957 This vapor is passed to a separate bed or zonewhich may be described as being essentially shallow (in comparison tothe liquid-coking bed hereinafter referred to), and is adapted toproduce a short-time vapor cracking at comparatively high temperature.Suitable quenching may be provided for the efiiuent of this vaporcracking.

Simultaneously with this high temperature, short-time vapor cracking, itis also possible in accordance with my invention to include a long-time,less drastic liquid-phase cracking. The liquid cracking bed will besufiiciently deep so that the deposited coke may have time to dry outand to thus produce at the lower end of the bed a substantially dryparticle. Vapors produced in the liquid-cracking or coking zone arepassed to the vaporcracking zone along with the vapors formed byflashing the charge stock.

In reheating the granular contact material to the temperatures requiredfor carrying out the respective reac-- tions, the contact material fromboth reaction zones is.

coking. The portion of contact material used for vaporphase cracking isthen passed to an outside high tempera-- ture reheating zone for furtherheating to a temperature.

sufiicient to carry out vapor phase cracking.

Control of combustion conditions in the secondary re-- heater providesthe required heat by the combustion of coke passing through thereheater. it is of course well known that the percentage of carbonmonoxide in mixtures of carbon monoxide and carbon dioxide resultingfrom the combustion of carbon at temperatures above 1400 F. greatlypredominates so that at 2000 F. better than CO is formed. Maintainingreheater temperature in such a temperature range provides a flue gasstream which when recycled to the primary or low temperature reheaterprovides on burning with excess oxygen a substantial amount of the heatrequired in the primary reheater.

One of the objects of this invention is to provide a new and improvedmethod and apparatus for economically effecting controlled cracking ofhydrocarbons by the use of a freely-flowing, gravity-packed bed ofgranular material, with a resulting conversion of hydrocarbons to coke,used in connection with a separate and independently controlled bed ofsimilar nature wherein vapors from the first bed may be converted tohigh yields of lower unsaturated hydrocarbons such as ethylene,propylene, and acetylene.

A further object of this method is to provide a hydrocarbon conversionsystem characterized by a high degree of flexibility and control andwherein the type and quality of the product may be more readily andconveniently controlled than has heretofore been the case.

A more specific object of my invention is to produce as a preferred endproduct, a high percentage of gaseous olefins by high temperaturecracking in a comparatively shallow, continuously moving, gravity-packedbed of granular coke.

A further object of my invention is to treat a residual oil to producecoke and an unsaturated gas as the only major end products.

A further object of my invention is to simultaneously perform a vaporphase cracking at high temperature and of short duration in one part ofa continuously moving bed of granular material, while simultaneouslyobtaining the optimum conditions for liquid phase cracking and coking ina separate and independently controlled bed of the same granularmaterial.

A further object of my invention is to set forth a system wherein amaximum utilization of heat may be mainelude materials containinglighter compounds.

. a H 2,789,084. 7 r

3 tained by virtuecf the incremental heating of a portion of a singlestream of flowing granular material.

A stillfurther object of my invention is to increase the efficiency of alow temperature and high temperature reheating operation by a moreefiective utilization of flue 7 gas.

Further objects and advantages of my invention will be apparent from thefollowing description of a-preferred embodiment of my invention taken inconnection with the attached drawing.

In the. customary cracking operation, whether in a tubular heater or ina catalytic fixed or flowing bed, it is well known that some portion ofthe products willbe lighter hydrocarbons having less than four carbonatoms to the molecule. Of these perhaps the most important is ethylenewhich is of considerable use in the petrochemical industry. Grdinarilythe production of ethylene is largely incidental and is somewhat smallbecause of the limited temperature conditions. Conventional crackingmethods for producing large yields of gaseous'olefins employ veryexpensive equipment which frequently requires the use of special alloys.Depositionof coke on the heating surfaces necessarily limits the lengthof the run. 'In these processes the charge stock is generally propane orsome other light distillate such as kerosene which is relativelyinexpensive. It is noted however that propane is not available in manysections of the country.

I have found that I can obtain largepereentages of the gaseous olefinsby feeding a heavy hydrocarbon directly into the hereinafter describedunit. This hydrocarbon may be a very. heavy oil, or a crude residue, andmay in- This is accomplished by applying the charge to a preheated,

gravity-packed, free-flowing body of granular material which ispreferably non-catalytic and may, for example,

be of a highly refractory nature. Examples of this material include'Alundumj Carb'orundum, pumice, fire brick, porous ceramic particles,spent catalyst, Koppel-s coke, petroleum coke, or other normallyinactive granular materials which can withstand temperatures up to 2600F. Coke is an ideal material for this process since it will withstandthe extremely high temperatures met in the process and since it may bereheated by partial combustion or partial conversion by the water gas orair gas reaction. It is to be noted hat the reactions referred to inthis description are essentially non-catalytic in nature, and may bebest described as thermal cracking.

By applying the hydrocarbon charge to the hot granular solids as theyenter the liquid-coking zone, I obtain a vaporization and cracking ofthe liquid constituents. Vaporous material removed from the liquidcracking or coking zone is sufficiently suitable in character so that itmay be used as a feed stock for the vapor cracking zone. By operating'inthis manner it is possible to avoid the difi'iculties arising from cokedeposition inherent in the vaporization, of these heavier components.Whereas I prefer to feed a liquid charge to the cokin'g'zo'ne, it ispossible that the charge can consist of a mixture of liquid and'vapor.

The conditions existing in gravity-moving beds of inert material areideally suited to both liquid and vapor cracking in the mannerhereinafter described. These conditions are substantially as follows(1') There is present a continuous, moving, non -turbulent mass ofheated solid particles which presents, in eifect, a continuouslysupplied clean heating surface.

(2) The rate of heat transfer and the particle surface area provided forheat transfer to the vapor phase crack.-

ing zone are both of a high order of magnitudepermittinghigh-temperature short-time cracking.

(3) Time factors are subject to precise control during operation. 7

' (4) Flexibility of operation maybe accomplished by the selectedremovalof the vapors at dilferentlevels' or distances of How. 7

(5) Maximum temperatures possible are 'g i'c atef than with heating intubular heaters. I

(6) The vapor cracking bed is relatively shallow as compared to theliquid bed. i

(7) If cracking is desired at low hydrocarbon partial pressures, steamor other gas may be introduced with the charge to produce the requiredeffect. Steam or gas is not required for the purpose of adjusting thecracking time, as in the case of high=temperature, short-time coilcracking. V 7 w (3) For deep or severecrackingoperations, this methodhas a unique advantage over coilcracking in that-the cracking reactionheat requirements are very. small or negligible. Where coke formationcannot be allowed, as in tubular cracking, the; reaction heats may be ashigh as 1000 B. t. u. per pound of charge when running for the optimumproduction of ethylene.

An illustrative form of embodiment of the apparatus in which I havefound it desirable to carry out jir'iyin- 'vention, is shown in theattached drawing in which the numeral 19 represents a receiver or'accuniulator'for the hot contact material. These hot inert granulespass through lines 11 and 12 under the control of valves 13 and 14respectively. The major portion of the particles passtoliquid-coking'reactor'15 hereinafter referred to as the first reactor,the liquid coker, o'r merely'the col-fer. The porous, inert, solidparticles are conveyed throughout the entire system solelyby gravityexcept as hereinafter referred to. 7 7

The reactor 15, as shown, tapers downwardly and outwardl'y from theinlet to the main portion, andthe n downwardly and inw'ardlyat thebottom'from the main portion to the outlet. This reactor ma befabricatedin substantially the same manner as therea'c'tor described indetail in U. S. 2,526,696. Itm'a be remap; reel 11'- gular as desired;Sealing steam may beap lieu' to the inlet line-1'2 of reactor '15" anare amines locations, i st generally shown, in the lines between thevarious v ssels hereinafter referred to. 'The purpose of this steam isto prevent the flow of gases an'cl' 'vapors from the vessels intoadjoining lines and vessels.

Hydrocarbon feed in line 16 is introduced into the flowing stream ofcontact materials in line 14 and is mixed therewith prior tointroduction him the reactor 15. If desired, feed16 could be introducedinto the'upper part of the reactor directly by a feed'meclianism such asdescribed in U. S. 2,326,696, so that a substantially'uniformdistribution of the hydrocarbon charge is obtained throughout thecross-sectional area of the reactor. It has been found however thatintroduction of the feed into the transfer line, such as 14, is to bepreferred since a better distribution of the hydrocarbon on the contactparticle can be obtained.

Asshownin the drawing, reactor 15 is provided with a vapor disengager1811 which is connected with vapor ing to regenerator or first heater23, is joined-them above by feed line id-through' which freshgranules'may be introduced to the system, and lihef 64 containing;granules from a source hereinafter referred to. These combined granulesare heated in regeneratorl tiby contbustio'n of a fuel gas admittedthrough line 25".iii'der the control" of va lvelfi andfliie' as recycledfi'o". thhi'ghtemperature reheater 45b? way of line 35in? 'Air foi'combustion is" admitted thfoiigli line" 2710135,! the t oll-' Ifdesired, steam may'be trol of valve 28. The granules only till vessel 23to the extent that an upper surface 23a is present. Thus the burnersheat the material at this surface.

Combustion gases pass downwardly through the bed concurrently with thedescending granules and leave through the holes 30 in the disengager 31and pass through the gas outlet 33. Disengager 31 is convenientlycentrally located in the chamber 23 and may have a cone top to aid indirecting the flow of particles. A short baflle 32 partially covers theholes 30 and further assist the flow of granules. Heated granulesintermittently leave the regenerator 23 through line 35 and pass throughvalve 36 to lift pot 37.

Lift pot 37 contains pressuring line 38 through which air or steam maybe passed under the control of valve 38a. Lift leg 42 enters pot 37 atthe top. At the top of lift leg 42 is located baffle 43 which arrest theflow of ascending material. Line 44 permits the lift gas introduced at38 to escape.

A portion of the elevated granules are passed to vessel 45 through line11 under the control of valve 13. This vessel is supplied with inletline 52 controlled by valve 54 and a flue gas outlet line 58. Heatingvessel 45 'is connected to vapor-cracking vessel 61 by line 60. Thislatter vessel has product outlet line 62 into which quenching medium maybe injected through line 63. Vessel 61 is provided with flow controlplates 61a similar to plates 21 of vessel 15 to regulate the particleflow.

Vessel 15 may be referred to as a reactor, a coker, a liquid-coker, oras a liquid cracker and coker and the term coking will be generallyapplied to the reactions occurring therein. Vessel 61 is a vaporcracker, or more simply a cracker. Vessel 37 is a lift pot, and vessel10, an accumulator or separator surge drum. Vessel 23, which 'may belocated above vessels 15 and 45, is a first re'generator or heater andvessel 45 is a second regenerator or heater.

' A particular embodiment ofthis process is designed to feed a WestTexas-New Mexico sweet residuum hav-. ing the following composition:

Gravity, API I Y I 14.2 Sp. gr., 60l60 1 09713 Color Black Pour point, FW 75 Viscosity, 'S. F. S. 210 F 180 Flash point, F., C. O. C. 680 Fire aF? C 0. -,f---.-.--.----:--1- Carbon residue, wt. percent:

' Ramsbottom 11.8 Conradson 13.0 Sayholt furol seconds. 2 Cleveland opencup.

This charge stock, heated to about 650-850 F., was introduced along withthe coke particles to the reactor by way. of line 14a. The cokeparticles in line 12 are normally at a temperature of 900l050 F.

The lighter materials are removed from the charge oil in the mannerhereinbefore referred to and the residual coke deposits evenly on thedescending bed as it passes through the coker. Due to the comparativelylong residence time in coker 15 (which may be 30 or 40 minutes), thecoke dries and becomes partially calcined; most of the volatiles areremoved therefrom. In this manner, a hard product coke is produced whichmay be withdrawn from the coker by line 29 under the control of a valvenot shown. This product, described more fully in applicants U. S. Patent2,600,078, June 10, 1952, may be briefly described as follows: dense(true density 1.9 g./cc.; apparent density 1.39 g./cc.), non-porous;hart (crushing strength for /2" particle 300 pounds, for particle 400500pounds; round-%" to 1.5" major dimension, regular, smooth, lowcoefficient of expansion, high specific heat, low volatile (less than-8%).

The major portion of the coke from reactor 15 is passed downwardlythrough line 22 to regenerat'or 23. Fuel, air and flue gasadmittedthrough lines 25, 27 and 58a regenerate the coke by heating itto about 900 F. Flue gases pass downwardly through the bed and leavethrough ports 30 in the disengager 31 and then through flue gas outlet33. The heated coke passes downwardly past baffle 32, through ports 30and line 35 to vessel 37.

When the proper amount of coke has been admitted to the vessel 37, thevalve 36 is closed and valve 38a: is opened, admitting steam to thebottom of the lift.. The regenerated or hot particles will then beconveyed through lift leg 42 to accumulator 10. This lift will. operateintermittently or continuously.

Fresh feed coke will be introduced through line 24ieither continuouslyor intermittently as conditions re-- quire.

Particles from vessel 10 are returned to the vessels 15 and 45. Underthe conditions hereinbefore set forth, from 40% to about of theparticles will be passed to the coker 15 although these limits willdepend entirely upon the particular operating conditions present and'the heat balance requirements for the individual zones..

When feeding a charge stock as hereinbefore set forth. in detail, anoverhead cut may be removed through line: 18 which has substantially thecharacteristics of a syn-- thetic crude oil of 20 to 30 API gravity.Such crude might be made up of essentially the following constit--uents:

Name Molecular Weight Wt. Percent 300 39.0 Recycle Stock 350 33. 4

Whereas a reduced cmde having the characteristics. described willproduce such a synthetic crude, if the: charge stock to coker 15 were aheavier bottoms, as for" example an asphalt, then the overhead in line18 would. be correspondingly heavier than the synthetic crude... Wherethe feed to the unit is somewhat lighter, as forexample a heavy crude,the overhead may consist of more components boiling within thegasoline-naphtha-- kerosene range. It is recognized, of course, that thecarbon content as measured by the Conradson test will vary for thesestocks generally increasing in the order:: heavy crude, reduced crude,asphalt.

The vapor product of the conversion in vessel 15 at a: temperature ofabout 900 F. is passed through line 18 to vapor cracker 61. At thispoint the vapors contact the hot descending particles which have beenheated to about: 1800 F. to 2000 F. (depending on the precise reaction:

' to be accomplished). These particles are usually cooled? by about600-800" F. as they pass through the reaction: vessel 61. The gaseousproducts leaving vessel 61 through: line 62 will contain acetylene,ethylene, propylene and: lesser amounts of methane, ethane, carbonmonoxide, carbon dioxide, as well as some tar and carbon. The vaporcontact time in vessel 61 is from 0.1 second to severah seconds.

For maximum yields of acetylene, the average temperature in the bed 61will be between about 2372 F. (1300 C.) and 2552 F. (1400 C.). At 1350C. the effluent gas will have about the following composition:

Percent Acetylene 35 Ethylene 4 v 23 Propylene 2 Benzene 5 Methane 15'CO and C02 2 Residues 18.

Percent Acetylene 1'6 Ethyl ne 42 Propylene a Benzene n 5 Methane Q0 andCO2 2 Residues a 10 PJlrerepropyler're'is the desirediproduct, thetemperature ismaintained between about l8 3t2 (100i) C.) and 2912 F.(l100 (1.). In this range the products from vessel 45 are as follows:

Percent Ac tyle e -uu Ethylene 40 Butylene "has", 3 Propylene ----V-Ethane a. a 18 Methane 8 Residues -a a 6 100 This represents aneconomically recoverable yield of propylene.

The possibility of achieving such satisfactory results is indicated bythe article to Hasche (Chem. and Met.) pages 78-79 (1942) and othersources.

The efiduent vapors leave the vessel 61 at' a temperature 200 400 F.below the entrance temperature of. the particles. The particles arecooled by as much as 400- 800 F. in passing through the vessel 61. Theyare then pasaedto the regenerator 23 in which theycomingle with theparticles from vessel 15. Since the temperature of the particles in line64 is higher than those in line 22, they p to reheat e ok from thecoking zone. This decreases the harden the regenerator 23. The pressurein the system is generally atmospheric or slightly higher, but seldomgreater than 50 p. s. i. g. V

The quench line 63@ is provided for introduction or liquid quench oil orother quench medium/by means of t which the temperature of the efiluentgases maybe reduced by burning fuel gases in line 24, thus heating thegranules.

as hereinbefore described.

Regeneration. in the h h emp rat re reheater is carried out by acontrolled'combustion ofthe coke particles at temperatures which producea flue gas predominating in carbon onoxide, 2060" F. thefi'u'e'gas willcontain b'et't'ci'tlian 90% carbon monoxide. The recycle of this fluegas through lines 5 8.and 58a to the primary reheater' 23 provides 311Milltional source of reheat fuel which substantially reduces overallfuel requirements. 7 H 7 It is of course to be noted that the particleshereinbefore referred to may be employed and that this process as hereincontemplated is substantially non-catalytic in' nature, its basic naturebeing thermal cracking.

At temperatures of approximately l haue shown andldescribed a preferredform of embodiment of n1 y invention, I am aware that -r nodificationsmay be made thereto andl-desire abroad :interpre-' tation of theinvention within the scope and spirit of the descriptionhereinandof theclaims appended hereinafter.

1. The process for thermally treating a heavy hydrocarbon charge tosimultaneously produce cokeandpredominant yields of gaseous unsaturatedhydrocarbonshaving less than four -carbon atorns to the moleculewhichcomprises continuously moving a continuous gravitypacked column ofTheatedsolid coke particles downwardly by gravity through a cokingoperation, continuously intro dueing said heavy hydrocarbon,a portion ofwhich is in the liquid phase, to the upperpart'of said column whereby aportion of said hydrocarbon charge is vaporized; maintaining thetemperature of said column in said coking operation suchas tomildlycrackthe liquid portion of said hydrocarbon charge whereby the unvaporizedportion of said hydrocarbon charge is ultimately convertedto dry coke.on the solid particles and to additional vapors, passing said cokedsolid particles through a lower part of said coking operation whereinsaid coke is dried on said coked particles, combining saidfirst-mentioned vapors and said additional vapors to form combinedvapors from said coking operation, passing said combined vapors to anindependent vapor-cracking operation containing an indepedent,continuously moving, continuous, gravity-packed column of solid coke.particles, maintaining said combined vapors in said vapor-crackingoperation fora period:

of from a fraction of a second to several seconds, maintaining thetemperature of said column in said vaporcracking operation in, the rangefrom 1200-2600? F. thereby producing an eflluent containing a highpercentage of unsaturated hydrocarbons containing less than four carbonatoms to the molecule, quenching .said eflluen't, withdrawing solidparticles from said liquidwokingoperation and said vapor-crackingoperation into a 'commou first heating operation, reheating saidparticles thereinto last-mentioned particles to said vapor-crackingoperation,

and drawing oil the not make of coke particles as product.

2. The process for thermally treating a heavy hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms tothemolcule as claimed in claim 1 wherein said .additional vapors andsaid first-mentionedvaporsare passed through said coking. operationconcurrently with theflow of said particles therein thereby aiding indrying 'said coked particles, and'thence countercurrent to said reheatedparticles in said independent vapor-cracking operation. I

3. The process for thermally treating a heavy hydrocarbon charge tosimultaneously produce coke andpredominant yields of gaseous unsaturatedhydrocarbons having less than four carbon atoms to the moleculclwhiehcomprises continuously moving continuous, gr av ity.- packed column ofheatedsolid coke particles downwardly by gravity through a'cokingoperation, connnoan ng troducing said residual hydrocarbon, the, major;pc'n'tirm of which is in the liquid phase,-v to transpa ent of saidcolumn whereby a portion of hydrocarbon. charge vaporized, maintainingthe temperature'oilsaid column,-

in said coking operation at approximately 9 00: Fa 1050 F. whereby theliquidportion of charge. is mildly cracked, the unvaporized portionthereof being I ultimately converted to dry coke on the solidcoke'p'arth cles and to additional vapors, passing said coked solid cokeparticles through a lower part of said coking operation, wherein saidcoke is dried on said solid coked particles, combining saidfirst-mentioned vapors and said additional vapors to form combinedvapors from said coking operation, passing said combined vaporsdownwardly through said coking operation and concurrent to the flow ofsaid particles therein thereby aiding in drying said coked particles,withdrawing said combined vapors from said coking operation at a pointbelow the surface thereof, passing said combined vapors to anindependent vaporcracking operation containing an independent,continuously moving, continuous gravity-packed column of solid cokeparticles, maintaining said combined vapors in said vapor-crackingoperation for a period of from a fraction of a second to severalseconds, maintaining the temperature of said column in saidvapor-cracking operation in the range from 1200 to 2600 F. therebyproducing an efliuent containing a high percent of unsaturatedhydrocarbons selected from the class consisting of acetylene, ethylene,propylene and mixtures thereof, quenching said effiuent, withdrawingsolid coke particles from said liquidcoking operation and saidvapor-cracking operation into a common heating operation, reheating saidparticles therein to a temperature of approximately 900 to 1050 F.,returning a portion of the reheated particles to said coking operation,passing the balance of said reheated particles through a second heatingoperation, heating said particles therein to a higher temperature thanthat in said vapor-cracking operation, and passing said last-mentionedparticles to said vapor-cracking operation.

4. The process for thermally treating a heavy hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule which comprises continuously moving a continuous gravitypackedcolumn of heated solid coke particles downwardly by gravity through acoking operation, continuously introducing said heavy hydrocarbon, themajor portion of which is in the liquid phase, to the upper part of saidcolumn whereby a portion of said hydrocarbon charge is vaporized,maintaining the temperature of said column in said coking operation atapproximately 900 F.-1050 F. whereby the liquid portion of saidhydrocarbon charge is mildly cracked, the unvaporized portion of saidhydrocarbon charge being ultimately converted to dry coke on the solidcoke particles and to additional vapors, passing said coked solid cokeparticles through a lower part of said coking operation wherein saidcoke is dried on said solid coked particles, combining saidfirst-mentioned vapors and said additional vapors to form a combinedvapor from said coking operation, passing said combined vapor to anindependent vapor-cracking operation containing an independent,continuously moving, continuous, gravity-packed column of the said solidcoke particles, maintaining said combined vapor in said vapor-crackingoperation for a period of from a fraction of a second to severalseconds, maintaining the temperature of said column in said vaporcracking operation in the range from 1200 to 2600 F. thereby producingan efiluent containing a high percentage of unsaturated hydrocarbonscontaining less than four carbon atoms to the molecule, quenching saidefiiuent, Withdrawing solid coke particles from said liquid-cokingoperation, reheating said solid coke particles therein to a temperatureof approximately 900 F.-1050 F., returning a portion of the reheatedcoke particles to said coking operation, passing the balance of saidreheated coke particles through a second heating operation, heating saidcoke particles therein to a temperature sufiicient to efiect saidshort-time, high temperature vapor reaction in said vapor-crackingoperation, and passing said last-mentioned coke particles to saidvapor-cracking operation.

5. The process for thermally treating a residual hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule as claimed in claim 4 wherein the temperature of saidvaporcracking operation is maintained between approximately 2000 F. and2300 F. to produce predominant yields of ethylene.

6. The process for thermally treating a residual hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule as claimed in claim 4 wherein the temperature of saidvaporcracking operation is maintained between approximately 2400 F. and2500" F. to produce predominant yields of acetylene.

7. The process for thermally treating a residual hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule as claimed in claim 4 wherein the temperature of saidvaporcracking operation is maintained between approximately l800 and2000 F. to produce predominant yields of propylene.

8. The process for thermally treating a residual hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule as claimed in claim 4 wherein the amount of coke passed to saidcoking operation is from about 3 5 to 4 times the amount passing to saidsecond heating operation.

9. The process for thermally treating a residual hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule as claimed in claim 4 wherein said heavy hydrocarbon charge isasphalt.

10. The process for thermally treating a residual hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule as claimed in claim 4 wherein said heavy hydrocarbon charge isa reduced crude.

11. The process for thermally treating a residual hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule as claimed in claim 4 wherein said heavy hydrocarbon charge isa heavy crude.

12. The process for thermally treating a residual hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule as claimed in claim 4 wherein products of combustion from thesecond heating operation are utilized in reheating coke particles fromthe liquid-coking operation.

13. The process for thermally treating a residual hydrocarbon charge tosimultaneously produce coke and predominant yields of gaseousunsaturated hydrocarbons having less than four carbon atoms to themolecule as claimed in claim 4 wherein the ratio of oxygen tocombustible carbon in the second heating operation is such that theproducts of combustion include a major portion of carbon monoxide andsuch combustion products are in part introduced to the first heatingoperation wherein the heat value thereof is utilized.

References Cited in the file of this patent UNITED STATES PATENTS2,388,055 Hemminger Oct. 30, 1945 2,526,696 Schutte Oct. 24, 19502,671,122 Goldtrap Mar. 2, 1954

4. THE PROCESS FOR THERMALLY TREATING A HEAVY HYDROCARBON CHARGE TOSIMULTANEOUSLY PRODUCE COKE AND PREDOMINANT YIELDS OF GASEOUSUNSATURATED HYDROCARBONS HAVING LESS THAN FOUR CARBON ATOMS TO THEMOLECULE WHICH COMPRISES CONTINUOUSLY MOVING A CONTINUOUS GRAVITYPACKEDCOLUMN OF HEATED SOLID COKE PARTICLES DOWNWARDLY BY GRAVITY THROUGH ACOKING OPERATION, CONTINUOUSLY INTRODUCING SAID HEAVY HYDROCARBON, THEMAJOR PORTION OF WHICH IS IN THE LIQUID PHASE, TO THE UPPER PART OF SAIDCOLUMN WHEREBY A PORTION OF SAID HYDROCARBON CHARGE IS VAPORIZED,MAINTAINING THE TEMPERATURE OF SAID COLUMN IN SAID COKING OPERATION ATAPPROXIMATELY 900*F.-1050* F. WHEREBY THE LIQUID PORTION OF SAIDHYDROCARBON CHARGE IS MILDLY CRACKED, THE UNVAPORIZED PORTION OF SAIDHYDROCARBON CHARGE BEING ULTIMATELY CONVERTED TO DRY COKE ON THE SOLIDCOKE PARTICLES AND TO ADDITIONAL VAPORS, PASSING SAID COKED SOLID COKEPARTICLES THROUGH A LOWER PART OF SAID COKING OPERATION WHEREIN SAIDCOKE IS DRIED ON SAID SOLID COKED PARTICLES, COMBINING SAIDFIRST-MENTIONED VAPORS AND SAID ADDITIONAL VAPORS TO FORM A COMBINEDVAPOR FROM SAID COKING OPERATION, PASSING SAID COMBINED VAPOR TO ANINDEPENDENT VAPOR-CRACKING OPERATION CON-